It is common to supply household liquids in containers sized for ease of handling. Some containers include structure which permits dispensing rather than pouring and these structures commonly involve some form of pump action. Because the containers are disposable, it is becoming more common for manufacturers to attempt to make the containers recyclable. However, pumps generally have numerous parts made from materials as diverse as stainless steel, rubber and various thermoplastic and thermohardening plastics. Consequently, pumps are becoming less acceptable.
A second difficulty with pump structures is cost and, although very efficient manufacturing methods keep the cost to an accepted level, there is no easy way of adapting pump technology to dispense more than one liquid at once without eventually doubling the cost of the pump parts.
This latter difficulty has been one of the key factors in limiting sales of product made up of two components which are to be kept separate until dispensed simultaneously. Such two-part products are not suitable for sale in containers which are used by simply pouring because of the inaccuracies of this procedure. There is therefore a need for a two-part dispenser having a simple structure and which is readily made without the complexities of a pump. It would be a benefit if such a dispenser could be designed to be made from materials which would permit all of it to be recycled without tedious dismantling and sorting of materials.
This invention also addresses another shortcoming of inverted liquid dispensers of the type which dispense in response to a squeezing action on the container. Typically the dispenser will provide the most liquid for a given squeeze when the dispenser contains the most liquid. As the amount of liquid decreases the dispenser contains more air and the compressibility of the air affects the amount of liquid dispensed.
This invention will also provide embodiments which are significantly less affected as the volume of liquid in the container is reduced.